<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<script>

    const saySomething = function () {
        this.name = '张三'
        console.log('ok', this.name)
    }

    function once(fn) {
        let called = false
        return function () {
            if (!called) {
                called = true
                fn.apply(this, arguments)
            }
        }
    }



</script>
</body>
</html>